Grinding machine



Ndv. 19, 1935 s, JACKSON 2,021,602

' GRINDING MAGHINE Filed May 3; 1933 4 Sheets-Sheet 2 L7 7% a2 a 'Nov.19,1935. P, 5 JA KSON 2,021,602

GRINDING MACHINE Filed M21313, 1953 '4' Sheets-Sheet 3 -Nov.19,1935 P, s, JACKSON 2,021,602

GRINDING MACHINE Filed May a, 19:55 .4 Sheets-Sheet 4 Patented Nov. 19, 1935 UNITED STATES- PATENT, OFFICE GRINDING mom Paul S. Jackson, Rockford, Ill., assignor to Sundstrand Machine Tool 00., Rockford, 111., a corporation of Illinois Application May 3, 1933, Serial no. 669,151 Y 15 Claims. (c1. 51-424) More particularly the invention relates. to a machine for the sharpening or grinding of tools,

it being an object of the invention to provide a new and improved machine of this character of simple construction and particularly adapted forthe accurate and eflicient sharpening of tools.

In sharpening tools, forexample, those such as are used in connection with machine tools, it is generally desirable, if not necessary, to perform not only rough and finish grinding operations on the tool, but also to hone'or lap the cutting edges of the tool. It is an object of the invention to provide a new and improved grinder embodying means for rough and finish grinding tools and also for honing the tools so that all of the finishing .operations may be performed thereon.

In order to secure the best results from cutting tools the clearance angles, top rake and side rake must be carefully maintained. It is an object ofthe invention to provide a novel grinding machine having work supporting means enabling an operator readily and accurately to obtain and maintain the desired angles.

Another object is to provide a tool grinder of new and improved construction embodying work supports enabling the operator to hold the tools manually in contact with the grinding wheels 80-. and also adapted to clamp the tools mechanically in the proper' position during the sharpening operation.

Another object is to provide a novel tool supporting mechanismfor a grinding machine embodying means for oscillating the tool support and also means for feeding the tool support toward the wheel.

Another object is to provide a feeding mechanism for a work support embodying cushioning means operable if the tool being ground is'fed too rapidly against the grinding wheel, to relieve any excessive tool pressure and to limit it to a predetermined pressure. Another object is to provide a newand improved grinder embodying three grinding wheels together with simple and eflicient means for driving the wheels from a single motor mounted in the base of the machine. Another object of the invention is to provide improved means for supplying an abundant amount of coolant to theroughand finish grinding wheels.

Further objects and advantages will-become readily apparent from the following detailed dethevline 4-4 of Fig. 2. 10.

Fig. 5 is a plan view, certain parts being shown in section.

Fig. 6 is an enlarged fragmentary view partly in section along the line 6-6 of Fig. 3.

Fig.7 is a fragmentary section along the lines 15 'l'| of Figs. 5 and 6. 1

Fig. 8 is a fragmentary section along the line P8 of Fig. 6.

Fig. 9 is a plan view of one form of tool guide.

Fig. 10 is a section along the line |0--ll of 20 'Fig. 9.

11 is a. section along the line- Il--l| of Fig. 4.

Fig. 12 is a plan view of a tool guide and clamping device.

25 Fig. 13 is a section along the line l3--|3 -o Fig. 12. v

While I have shown in the drawings and shall herein describe-in detail a preferred embodiment of. my invention particularly adapted for sharp- 30- ening cemented carbide tools, it is to be understood that I do not thereby intendto limit the invention to the specific form or arrangement disclosed, but aim to cover all modifications and alternative constructions falling within the spirit 35 and scope of the invention as expressed in the appended claims.

;As illustrated in the drawings, the invention comprises generally a frame or pedestal 20 (Fig.

1), a rough grinding wheel 2| and a finish grind- 40 ing wheel 22 mounted on the opposite ends of a horizontal double ended spindle 23, rotatably I mounted in the upper portion of the pedestal and projecting from the opposite sides thereof, a honing wheel 24 mounted on the front end of a 45 spindle 25 rotatably mounted in the upper portion of the pedestal and extending forwardly therefrom, oscillatory work supports 26 and .21

adjacent the wheels 2| and 22' and an adjustable work support 28 adjacent the wheel 24. The 50 grinding wheel spindles are arranged to be driven by an electric motor 29 (Figs. 2 and 4) positioned in the lower portion of the pedestal. The rough and finish grinding wheels-are arranged to be supplied with coolant from a reservoir 3. by

means including a pump 8| and conduits 82 and 88.

In the preferred form of the invention the pedestal 28 comprises a hollow base portion 85 and a hollow top frame element or casing 36 secured thereon by means of bolts 31. The double ended spindle 23 is rotatably mounted in the upper portion of the casing 38 (Fig. 2) by means of anti- I friction bearings 38 and 89 so arranged as to prevent end play of the'spindle and to provide the necessary thrust support. The spindle 25 ispositioned at right angles to the spindle Hand is rotatably mounted by means of an antifriction bearing 48 in the forward wall of the casing, and a second antifriction bearing 4| mounted in a bracket 42 formed integrally with and extending inwardly from the forward casing wall, so as to provide bearings on the opposite sides of a pulley 48 on the spindle. This pulley as well as a double pulley 44 on the spindle 23 are connected with a multiple pulley 45 (Figs. 2- and 4) on the shaft of the motor 28 by means of belts 48, 41 and 48. In

- order to provide for adjustment of the tension ber and the feet on the motor so as to absorb vibration and eliminate the transmission of noise between themotor and base. The front of the.

base has an opening therein, covered by a screen.

81 so as to provide the necessary ventilationfor the motor.

The work supports 28 and 21 for the rough and finish grinding wheels are preferably adapted for an oscillatory movement across the face of the wheels and also for a feeding movement toward the wheels and; as illustratedherein, are pro- 7 vided with angularly adjustable work holders 56 and 51 movable about axes extending transversely of the spindle 23. The means for mounting the work supports comprises a cylindrical bar 58 which extends through suitable apertures in the side walls of the casing 38 and projects outwardly therefrom and into cylindrical recesses 58 inthe work supports, handles 86 being provided on the opposite ends of the support so that an operator may oscillate the work support manually. Since, in the preferred embodiment of the invention, the work supports 28 and 21, and the parts associated therewith, are substantial duplicates of each other, only one will be described in detail.

Referring more particularly to Figs. 1, 2 and 6, the bar 58 is shown ashaving a flat surface 58 on the lower side of its right hand end. A similar flat surface is provided on the other end of the bar. A flat ended cylindrical member or plug 8| ,is slidably mounted in a recess 82 in the lower portion of the support 21 and is arranged to engage the flat surface on the bar 58. In order to clamp the plug 8| against the bar so as to hold the work support rigid with the bar, a bushing 88 is threaded in the lower portion of the recess 52 and has a closed outer end to which is secured an operating handle 84.- By screwing thebushing 88 upwardly the work support can be clamped in position. By loosening the bushing the work support may be oscillated through an angle determined by the amount of play between the plug BI and the bushing. Preferably a coiled spring 65 isinserted intermediate theplu'g 8i and the closed end of the bushing 88 so as to have a tendency to return the work support to its normal horizontal position. I

Means in the form of a screw and nut mecha- 5 nism is herein provided for feeding the work support 21 longitudinally of the bar 58, a screw 18 carried on the bar -58 engaging a nut 1| rotatably mounted in the forward portion of the support 21. As illustrated most clearly in Fig. 6 the rear end of the screw extends into a recess 12 in the end of the bar 58 and hasan annular member or collar 13 secured thereto forming the middle race of. a double ball thrust bearing, and cooperates with a series of balls 14 and a race 15 to prevent 15 movement of the screw toward the left, the race 15 abutting against the inner end of the recess 12.

.A series of balls 18, together with a race 11 coh operate to form the other portion of the thrust bearing. This race and set of balls are held in an engagement with the collar 13' by means of a coiled spring 18 positioned intermediate the race 11 and a shoulder formed on an adjustable bushing 19 which is screw threaded'in the end of the "recess 12.- The tension of the coiled spring 18 35 is in this way readily adjustable by means of the bushing 18 fora purpose hereinafter more fully set forth. The nut 1| is.generally cylindrical in form and has a peripheral groove 88 in which an arcuate shoe 8! fits. This shoe is secured to a plate 82 forming a portion of the work support 21 by means of a set screw 88 so as to permit rotary movement of the nut 1| and prevent longitudinal movementthereof. The nut is arranged to be operated manually by means of a pair-of and tlie support 21 is fed toward the grinding wheel at too rapid a pace by means of :the screw and nut mechanism, the feed screw 18 can move toward the right (Fig. 6) with respect to the bar 58 so that the pressure on the tool will be determined by the coiled spring 18.

In addition to this cushioning means, means is provided .so that the work support 21 will not be movedv toward and away from the grinding wheel during oscillatory movement thereof with respect to the bar 58. This means is herein disclosed as comprising, in addition to the rotary mounting means for the screw on the bar, a pair 50 of members 88 (Fig. 8) secured to the member 82 in laterally spaced relation and having their adjacent sides engaging a flattened portion 81 on the screw 18. Thus when the work support 21 is oscillated, the nut 1| and also the screw 18 are oscillated with the support, the oscillatory motion of the screw with respect to the bar 58 being permitted by the double thrust bearing. 1

The work holder 51 (Figs. 1, 2, 5 and 6) which is mounted for angular adjustment with respect to the work support 21 about the ways extending transversely of the grinding wheel axis is herein shown as provided with arcuate bevelled surfaces 88 engaging corresponding bevelled ways 8| on the work support 21. The holder 51 is arranged to be adjusted by means of a manually operable handle 92 secured on the outer end of a shaft 33 which is rotatably mounted on the support 21 and has a worm 94 on its inner end engaging worm wheel teeth 95 formed on the adjacent periphery of the work holder 51. This worm and worm wheel also operate to hold the work holder.in its adjusted position. Preferably extending upwardly therefrom. The work sup- 6 a scale 96 is provided on one end of the work holder and cooperates with a'zero mark 91 (Fig. 5) on the support 21 to indicate the angular position of the holder. As illustrated in the drawings the work holder is provided with a T-slot 98 and its associated parts and operating mechanisms are substantial duplicates of the work support 21 with the exception that. the angular adjusting means for the work holders are both placed adjacent the front side of the machine as shown in Fig. 5. The work support 28,fr the honing wheel 24, however, may be diiferent in form because of the-fact that when tools are being honed they-are generally applied to the wheel manually by the operator.

As illustrated herein the work support 28 is.

carried on a cylindrical bar I which has one end rigidly secured to the front wall of the casing 36 (Fig. 4) and projects forwardly therefrom. A split clamping member I06 has an annular portion surrounding thebar I05. and a split part port 28 has a pair of laterally spaced downwardly extending brackets I0I engaging the opposite ends of the split portion of the clamping member, as shown in Figs. 1 and 11. A rod I08 extends through slots I00 in the split portion of the clamping member I06 and through circular apertures H0 in the brackets I07, as illustrated most clearly in Fig. 11. The portion of this rod extending through the split portion of theclamping member is preferably .flattened on opposite sides so as to be held non-rotatably in the clamping member.

head being in theform'ofi a bevelledcollar II2 having graduations II 3 thereon arranged to cooperate with a zero mark on the adjacent member I0'I to indicate the angular position of the work support. The other end II4 of the rod is threaded and carries a handle II5 a portion-of which forms a clamping nut. Thus the clamping rod and nut just described perform three functions, the first of which is to secure the clamping member I06 to the bar I05, the second to secure the workholder 26 to the clamping member I06,

and the third to permit of angular adjustment of the work holder with respect ,to the clamping member. If desired. a'rey IIG may be provided for holding the clamping member I06 in its upright position. -.As illustrated most clearly in Figs. 4 and 5 the top of the support 28 forms preferably provided with a T-slot II] in case an rounding the tool holders. The 'end portions IIO of the rod, however, are cylindrical so as to permit the work' support 28 to be. adjusted angularly. At one end the rod I08 is headed at. I, a portion of the against the wheels. erally desirable to provide a guide means against which the tool may be held during the feeding or oscillatory movements of the work support. Such 76 I operator finds it desirable to secure a guide or other device to the top of the support.

,Protective hoods I20, I2I and I22 are provided for the grinding wheels and, as illustrated herein, are adjustable angularly and longitudi- 5 nally of the wheels on cylindrical mounting members I23,v I24 and I25, respectively, carried on the casing 36 so that, as the cup shaped wheels wear, thehoods may be moved back to leave the face of the wheels properly exposed. Suitable headed screw devices I26 (Fig. 5) are provided to secure the hoods in their adjusted positions. As illustrated in Figs. 1, 2 and 4, the coolant supply conduits 32 and 33 have valve devices I30 and I3I, respectively, and connect to ports, I32 and I I33 formed in the upper portions of the hoods I and I2 I. Adjustable nozzle members I34 and I35 are threaded into the outer ends of the ports I32 and I33 and are arranged to direct the coolant against the cutting portions of the 20 wheels. v

The invention provides a novel means for supplying cutter coolant. Thus as illustrated in Fig. 4, the rear side of the base is provided with an opening I36 and the tank 30"is fitted into said opening. The bottom of the tank is provided with a pair of laterally spaced lugs. I38 arranged to straddle a portion of the rear wall of the base, and notched lugs I38 (Fig. 5) are provided on the top sides of the tank arranged to engagesoboth sides of the rear wall of the base to secure the tank in an upright position. In this way it is merely necessary to lift the tank slightly by means of handles I39, to remove it from the base,

the notched lugs thenpassing out through op- 3.;

posed recesses I36 (Fig. 2) which widen the opening I36 at the level of the lugs in the raised position of the tank. A partition wall I40. is shown herein centrally of the tank'to divide it into compartments MI and I42. drawn out of. the compartment I4I through a pipe- I43 which leads to the intake of the pump 3|. The outlet of v the pump is connected by means of apipe I44 to the conduits 32 and 33. The coolant discharged against the grinding 5 wheels drains into the lower portions of the work supports 26 and 21 which are provided with side which is secured to a bracket I50, hung from the to.

bar 58, and adjustably clamped thereto by means of a screw device I5 I. The pump is provided with a pulley I52 mounted on a shaft I53 and has an outboard bearing I54 for the shaft. .The pump pulley is so. positioned as to engage the twisted 5 run of.- the belt 46 (which is V-shaped on both sides) and is not only driven by the belt 46, but serves as an idler and direction pulley for the belt,

as illustrated most clearly in Fig. 2.

' If desired, the tools being ground may be sup- 70.-

ported on the work holders and held manually If this is the case it is gen- Coolant is a guide means for a tool is herein illustrated in Figs. 9 and- 10,'and in Figs. 1 and 5, in connection with the work holder 58. A cylindrical member I80 has an inverted T-shaped portion I8I operable in the T-slot 98 and is slidable longitudinally of the slot. An apertured rectangular member I82 fits over the cylindrical member I80 and is adjustable angularly thereabout, a screw device I83 being threaded in the member I 82 with its 10 inner end engageable in'a groove I84 in the member I80, to secure the guide member I82 in its angularly adjusted position. Preferably a scale I85 on the member I80 cooperates with a zero mark I88 on the guide member I82 to indicate the angle to which the guide member is adjusted. In use a tool I81 (Fig. 5) is held against a side of the guide member I82 during the grinding operation.

Attimes it is preferable to clamp a tool rigidly to the work holder and to control the feeding of the tool against thewheel by means of feeding mechanism for the work support. Such a clamping device is illustrated in Figs. 12 and 13 for clamping a tool I88. This device comprises acylindrical post I89 having its lower end in the form of an-inverted T slidably engaging in a T-slot on the work holder 58. A. tubular bushing I10 surrounds. the lower portion ofthe post 488 and has straight'sided recesses HI and I12 therein, the recess I1I receiving a portion of the tool I88. A collar I13 is non-rotatably secured on the upper end of the post I89 and carries a set screwf'i" engaging in a keyway I18 in the post to prevent rotation of the collar with respect to the post. A headed clamping screw I18 extends through a washer I11 on top of the collar I13 and into screw threaded engagement with the post- Since the bushing I10 is rotatable with respect to 1 the post the tool I88 may be adjusted to any desired angle. This angle may be indicated by 40 means ofa scale on the bushing I10 cooperating with aura mark on the collar I13, since the posi: tionofthecollarisflxedwithrespectto theT- slot by means of a set screw I14. After the proper angular adjustment the clamping screw I18 may be tightened and the tool I88 then moved by oscillating or feeding the work support.

It will be readily apparent that as disclosed herein the invention provides a grinding machine capable of performing rough grinding, finish grinding and also honing operations, and that the work supporting and feeding mechanisms per- I mit of holding the tools at desired anglesand maintaining these angles during the grinding of the tool. The provision of means for cushioning the feeding of the tool against the grinding wheels eifectively prevents any injurious pressures on-the tool, and the novel formof feeding mechanism eliminates any possibility of the tool being fed toward the wheel during the oscillatory movement of the work-holders.- .Theresult is a machine particularly adapted for the grinding and finishing of tools such as those made of cemented carbide, as well as other materials. I claim as m invention:

\ 1. In agrinding machine of the character described having a hollow pedestal, a first grinding wheel spindle rotatably mounted in said pedmtal.

, and projecting from a side grinding wheel spindle rota ably mounted in the pedestal and projecting from the front w 111 thereof, pulleys on'said spindles,.an electric motor in the pedestal and .having a driving shaft parallel to one of said spindles, a multiple pulley on said driving shaft, a belt connecting said multiple 7 pulley with the pulley It the parallel mlndle, a

estal parallel to one' of said spindles, a bracket all thereof, a second secondbelt connecting said multiple pulley with the puley on the other spindle through a quarter turn, a cylindrical work support mounting bar extending into and projecting out from said pedsecured to said bar within the pedestal, and an idler pulley rotatably mounted on said bracket for guiding said quarter turn belt.

2. In a grinding machine having a cylindrical supporting bar and a work support mounted for 10 feeding movement longitudinally of the bar and oscillatory movement about the bar. means for feeding the work support comprising a feed screw coaxial with said bar and having one end positionedinarecessinone endofthebarsoasto 15 project therefrom, a double thrust antifriction bearing having its center race secured to said screw, one end race positioned against the bottom of said recess and the other end race surrounding the screw, a bushing threaded into said 20 recess, a coiled spring positioned intermediate said bushing and the adjacent raceof the bearing, anut for said screw rotatably mounted on the work support, means for preventing longitu-' dinal movement of the nut relatively to the work 9.5 support, means for rotating said nut, and means for preventing rotation of said screw relatively to the work support. K

3. In a grinding machine having a cylindrical supporting bar and a work support mounted for 30 feeding movement longitudinally-thereof and oscillatory movement thereabout, means for feeding the work support comprising a feed screw coaxial with said bar and having one end positioned in a recess in one end of the bar so as to 35 project therefrom, a double thrust antifriction bearing having its center race secured to said. screw, one end race positioned against the bottom of said recess and the other end race surrounding the screw, a bushing threaded into said recess, a 40 coiled spring positioned intermediate said bush ing and the adjacent race of the bearing, a nut for said screw mounted on the work support, and means for rotating one element of the screw and nut device. a

4. Ina grinding machine having a cylindrical supporting member constituting a first part and a work support mounted for feeding movement longitudinally thereof and oscillatory movement thereabout and constituting a second part, means 5 for feedingthe work support comprising a feed screw and nut device, one element of which is carried on one of said parts and the other on the other part, a double thrust antifrlction bearin having its center race secured to one of said ele- 55 ments, one end race positioned against its supporting partandthe other endrace surroundingthe element, a bushing onto said part, a coiled spring pofltloned intermediate said bushingandtheadjacenttaceofthebearinglmeansw for preventing longitudinal movement of the other element ofsaid device relatively to the supporting part, means for rotating one of said elements, andmeans for oscillatingthe element on the work support with the work support. 05

5. In a grinding machine having a cylindrical supporting bar and awork support mounted for oscillatory movement about the bar, and means. for limiting the-oscillatory movement of the support comprising a part slidably mounted on said 70 from the bar and thereby limit the oscillatory 1's movement of the support, ,a coiled spring positioned intermediate said member and said part pressing said part against said flattened surface of the bar and tending to return the work support to its normal position, and a manual control device for adjusting said member.

6. In a grinding machine having a cylindrical supporting bar and a work support mounted for oscillatory movementabout the bar, and means for limiting the oscillatory movement of the support comprising a cylindrical plug slidably mounted in a recessin said work support for movement substantially radially of the bar and arranged to engage a flattened portion of said bar, a bushing threaded in said recess and adjustable to limit'the movement of said plug away from the bar and thereby limit the oscillatory movement of the support, a coiled spring positioned intermediate said bushing and said plug pressing said plug against said flattened surface of. thebar and tending to return the work sup port to its normal position, and a manual control device for operating said bushing, said bushing being adapted to be rotated sufliciently to force said plug firmly against the flattened surface of the bar so as to clamp the work support rigidly to the bar and prevent oscillatory moveinent of the work support.

7. In a grinding machine having a cylindrical supporting member constituting a first part, and a work support mounted for feeding movement longitudinally thereof and oscillatory movement thereabout and constituting a second part, means for feeding the work support comprising a screw and nut device, one element of which is carried on one of said parts andthe other on the other part, a double thrust bearing having its center race secured to one of said elements, one end race positioned against the supporting part of that element and the other end race surrounding that element, a member threaded ontosaid last mentioned part, a coiled spring positioned intermediate said member and the said other race of the bearing, means for preventing longitudinal movement of the other element of said device relatively to its supporting part, means for retating one of said elements, and means for 05011-- lating the element on the work support with the work support.

8.-In a grinding machine having a cylindrical supporting member constituting a first part, and a work support mounted for feeding movement longitudinally thereof and oscillatory movement thereabout and constituting a second part, means for feeding the work support comprising a feed screw and nut device, one element of which is carried on one of said parts and the other on the other part, a double thrust antifriction bearing V having its center race secured to one of said elements, one end race positioned against its supporting part and the other end race surroundin the element, a bushing threaded onto said part, a coiled spring positioned intermediate said bushing and the adjacent race of the bearing, means for preventing longitudinal movement of the to be driven therefrom.

and parallel to the spindle axis, a work support I mounted on the free end of said bar, a-work holder mounted for angular adjustment on said work support about an axis extending transversely of the spindle axis, means for adjusting the angular position of said work holder including a manual control handle mounted on said work. support in front of said grinding. wheel,- means for feeding said work support longitudinally on said bar including a second manual control handle mounted on said Work support in front of said grinding wheel, and means for limiting the oscillatory movement of the work support on the bar and for clamping the work support to the bar including a manual control handle positioned beneath the work support.

10. In a grinding machine having asupport a grinding spindle rotatably mounted on a horizontal axis and projecting from said support, a cup shaped grinding wheel on said spindle, a 20 cylindrical bar extending from the support be-' neath and parallel to the spindle axis, a work support mounted on the free end of said bar, a work holder mounted for angular adjustment on said work support about an axis extending trans-- versely of the spindle axis, means for adjusting wheel spindle rotatably mounted in said pedestal and projecting from a side wall thereof, a second grinding wheel s'pindlerotatably mounted in the pedestal and projecting from the front wall thereof, pulleys 'on said spindles, an electric motor in the pedestal and having a driving shaft parallel to one of said spindles, a multiple pulley on said driving shaft, a belt connecting said mul- 5 tiple pulley with the pulley on the parallel spindie, a second belt connecting saidmultiple pul ley with the pulley on the'other spindle through a quarter turn, a bracket adjustably mounted within said pedestal, secured to said bar within 50 the pedestaLmeans for supplying coolant to one or more grinding wheels on said spindles including a pump mounted -on said bracket, and a drive pulley for said pump engaging said quarter turn belt so as to act as a guide for the belt and 12. A tool-sharpening machine comprising, in combination, a hollow pedestal adapted for floor mounting and of relatively large substantially rectangular horizontal cross section, rough and 00 finish grinding wheels, a first spindle on said pedestal rotatably supporting said wheels on horizontal axes substantial-1y waist-high, and facing outwardly from the pedestal on opposite sides thereof, work supports mounted on said pedestal beneath said grinding wheels for oscillatory movement transversely of the grinding wheel axes, means for feeding said supports to- I ward the grinding wheels axially thereof, a honing wheel, a second spindle rotatably supporting said honing wheel substantially waist-high on a horizontal axis and extending outwardly fromthe forward side of the pedestal, a worksupport: carried by said pedestal beneath said honing wheel, a coolant supply reservoir mounted on the rear side of said pedestal, a pump mounted within said pedestal, and an electric .motor mounted within said pedestal adjacent to the bottom thereof and having a belt driving connection with said first spindle-and a.single belt driving said-pump and said second spindle.

13'. A grinding machine having, in combination, a frame comprising a-hollow base pedestal and a top frame element detachably secured thereon, a spindle journalled in said top frame element and projecting therefrom to receive a grin in wheel, a supporting bar also projecting from said top frame element, a work support mounted on said bar, and a coolant supply reser- 'voir removably mounted in and forming part ofa wall of said base pedestal.

14. In a grinding machine having a cylindri-l cal supporting bar and a work support mounted thereon for feeding movement longitudinally of. the bar and oscillatory movement about the bar,

means for feeding saidwork supp rtduring a" grinding operation comprising a feed screw and nut deviceyone element of which is rotatably 2,021,602 Y "carried on said bar and the other is rotatably carried on said support, means for rotating one element of said device to feed the. support, and means for oscillating the element carried on said bar with said support when the same is oscillated 5 to prevent feeding movement of the support by relative rotation of the elements.

15. In a grinding machine having a cylindrical supporting bar and a work support mounted thereon for feeding movement longitudinally of 10 the bar and oscillatory movement about the bar,

means for feeding said. work support during a grinding operation comprising a feed screw ro-t tatably supported at one end by said bar, a nut threaded onto said screw and rotatably mounted 5 

